diff options
| -rw-r--r-- | net/core/sock.c | 43 |
1 files changed, 40 insertions, 3 deletions
diff --git a/net/core/sock.c b/net/core/sock.c index b164618f2cb6..be20a1af20e5 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -146,6 +146,9 @@ static DEFINE_MUTEX(proto_list_mutex); static LIST_HEAD(proto_list); +static void sock_def_write_space_wfree(struct sock *sk); +static void sock_def_write_space(struct sock *sk); + /** * sk_ns_capable - General socket capability test * @sk: Socket to use a capability on or through @@ -2324,8 +2327,20 @@ void sock_wfree(struct sk_buff *skb) { struct sock *sk = skb->sk; unsigned int len = skb->truesize; + bool free; if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) { + if (sock_flag(sk, SOCK_RCU_FREE) && + sk->sk_write_space == sock_def_write_space) { + rcu_read_lock(); + free = refcount_sub_and_test(len, &sk->sk_wmem_alloc); + sock_def_write_space_wfree(sk); + rcu_read_unlock(); + if (unlikely(free)) + __sk_free(sk); + return; + } + /* * Keep a reference on sk_wmem_alloc, this will be released * after sk_write_space() call @@ -3191,20 +3206,42 @@ static void sock_def_write_space(struct sock *sk) /* Do not wake up a writer until he can make "significant" * progress. --DaveM */ - if ((refcount_read(&sk->sk_wmem_alloc) << 1) <= READ_ONCE(sk->sk_sndbuf)) { + if (sock_writeable(sk)) { wq = rcu_dereference(sk->sk_wq); if (skwq_has_sleeper(wq)) wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND); /* Should agree with poll, otherwise some programs break */ - if (sock_writeable(sk)) - sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); + sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); } rcu_read_unlock(); } +/* An optimised version of sock_def_write_space(), should only be called + * for SOCK_RCU_FREE sockets under RCU read section and after putting + * ->sk_wmem_alloc. + */ +static void sock_def_write_space_wfree(struct sock *sk) +{ + /* Do not wake up a writer until he can make "significant" + * progress. --DaveM + */ + if (sock_writeable(sk)) { + struct socket_wq *wq = rcu_dereference(sk->sk_wq); + + /* rely on refcount_sub from sock_wfree() */ + smp_mb__after_atomic(); + if (wq && waitqueue_active(&wq->wait)) + wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT | + EPOLLWRNORM | EPOLLWRBAND); + + /* Should agree with poll, otherwise some programs break */ + sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); + } +} + static void sock_def_destruct(struct sock *sk) { } |